Why is my bearing suddenly making excessive noise?

Bearings are critical components in any piece of rotating machinery. Their primary function is to support the rotating shaft whilst reducing friction to facilitate smooth motion.

Due to the vital role that bearings play within machinery, it’s important to regularly inspect your bearings for any issues, whilst ensuring that maintenance is carried out on schedule.

If you notice that your bearing has suddenly become noisy, you’re probably wondering what’s going on. Why is your bearing making a noise and what should you do about it?

Read on to discover the causes of a noisy bearing and the next steps that you should take.

What causes a bearing to be noisy?

If your bearing has suddenly started making a noise during operation, there is a problem with your bearing. The excess noise that you’re hearing is created when the raceways of the bearing have become damaged, causing the rolling elements to bounce or rattle during rotation.

There are many different causes of a noisy bearing but the most common is contamination. It could be that contamination occurred during the installation of the bearing, with particles remaining on the raceway which caused damage when the bearing was first operated.

Shields and seals can become damaged during lubrication of the bearing, rendering them ineffective in protecting against the ingress of contamination – a particular problem in highly contaminated environments.

Contamination is also common during the lubrication process. Foreign particles may become stuck to the end of the grease gun and enter the machinery during relubrication.

These foreign particles make it into the raceways of the bearing. When the bearing begins operation, the particle will start to damage the raceway of the bearing, causing the rolling elements to bounce or rattle and creating the noise that you are hearing.

What should you do if your bearing starts making noise?

The noise coming from your bearing may sound like a whistling, rattling or growling. Unfortunately, by the time you hear this noise, your bearing has failed and the only solution is to replace the bearing as soon as possible.

You may find that adding grease to your bearing quietens the noise. That means it’s fixed the issue, right?

Unfortunately, this isn’t the case. Adding grease once your bearing has started to make a noise will only mask the issue. It’s like putting a plaster on a stab wound – it needs urgent attention and the noise will only come back.

You can use condition monitoring technologies such as vibration analysis or thermography to predict when the bearing is likely to fail catastrophically and to calculate the latest point at which you can safely replace the bearing.

How to prevent bearing failure

It can be tempting to just replace the failed bearing and carry on with your everyday business operations. However, it’s important to not just replace the bearing but to also look for the root cause of the failure. Performing root cause analysis will identify the underlying issue, allowing you to put mitigating measures in place to prevent the same issue from reoccurring.

Making sure you’re using the most effective sealing solution for your operating conditions and checking the condition of your seals every time you perform maintenance can help to guard against the ingress of contamination.

It’s also important to make sure you’re using the right fitting tools for your bearings. This will help to prevent damage from occurring during the mounting process.

Monitor your bearings

Continuously monitoring your bearings gives you the best chance of quickly identifying and addressing potential issues with your bearing. Condition monitoring systems are a great way to keep the health of your machinery under constant review.

At ACORN, we supply the SKF range of condition monitoring equipment, from stroboscopes and vibration sensors to full condition monitoring systems which integrate seamlessly with your machinery for remote monitoring.

Take home message

If your bearing has suddenly become noisy during operation, it has already failed. It may still be able to operate for now but it will be getting closer and closer to catastrophic failure. The most common cause of a noisy bearing is contamination which damages the raceways of the bearing, causing the rolling elements to bounce or rattle.

The only solution to a noisy bearing is to replace the bearing. Applying grease will only mask the issue.

If you need advice about a troublesome bearing, or help identifying the root cause of your bearing failure, contact our bearing experts today.

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